config.js

/**
 * This is a browser shim for the `config` module that gets its configuration
 * values from `next/config`. It supports the `get()` and `has()` methods but
 * not extras like `config.util`. Since this file will not be transpiled, it
 * must use syntax supported by all browsers.
 */
var getConfig = require("next/config").default;

/**
 * Underlying `get` mechanism.
 *
 * Adapted from `node-config`.
 */
function getImpl(obj, property) {
  var keys = Array.isArray(property) ? property : property.split(".");
  var value = obj;
  for (var i = 0; i < keys.length; i++) {
    if (value === null || typeof value !== "object") {
      value = undefined;
      break;
    }
    var key = keys[i];
    value = value[key];
  }
  return value;
}

/**
 * Get a configuration value.
 *
 * This will return the specified property value, throwing an exception if the
 * configuration isn't defined. It is used to assure configurations are defined
 * before being used, and to prevent typos.
 *
 * Adapted from `node-config`.
 */
function get(obj, property) {
  if (property === null || property === undefined) {
    throw new Error("Calling config.get with null or undefined argument");
  }
  var value = getImpl(obj, property);
  if (value === undefined) {
    throw new Error('Configuration property "' + property + '" is not defined');
  }
  return value;
}

/**
 * Test that a configuration parameter exists.
 *
 * Adapted from `node-config`.
 */
function has(obj, property) {
  if (property === null || property === undefined) {
    return false;
  }
  return getImpl(obj, property) !== undefined;
}

var runtimeConfig = getConfig();
var serverRuntimeConfig = runtimeConfig.serverRuntimeConfig;
var publicRuntimeConfig = runtimeConfig.publicRuntimeConfig;
var nodeConfigServerKey =
  publicRuntimeConfig.nodeConfigServerKey || "serverRuntimeConfig";
var nodeConfigPublicKey =
  publicRuntimeConfig.nodeConfigPublicKey || "publicRuntimeConfig";

var config = {};
config[nodeConfigServerKey] = serverRuntimeConfig;
config[nodeConfigPublicKey] = publicRuntimeConfig;
config.get = get.bind(config, config);
config.has = has.bind(config, config);

module.exports = config;